Electrolytic deposition of nickel from nickel salt solutions



UNITED STATES, PATENT OFFICE,

ELECTROLYTIC DEPOSITION OF NICKEL FROM NICKEL SALT SOLUTIONS Anton Martin Gronningsaeter, New York, N. Y., assignor to Falconbridge Nickel Mines Limited, Toronto, Ontario, Canada No Drawing. Application August 15, 1933, Serial No. 685,224. In Norway August 27, 1932 3 Claims. (Cl. 204-14) This invention relates to the electrolytic depoon the contrary, the small amounts of dilute sition of nickel from nickel salt solutions as emacid adhering is an advantage. It has been ployed in the metallurgy of nickel. found that immediate introduction in the dep- In the usual processes of electrolytic refining osition tanks is not necessary, so that a consid- 5 of metals, the deposition of the metal is freerable number of prepared'starting sheets, for 5 quently effected on so-called starting sheets or instance about the thirty to sixty plates usually plates of the same metal as that to be deposited. needed for one or two deposition tanks can be Such starting sheets are employed for example removed from the pickling tank at a time. in the refining of copper, lead and nickel. In The preparatory acid treatment of the nickel these known processes these starting sheets sheets is suitably carried into eifect by placing 10 have not been subjected to any preparatory the sheets intanks containing dilute sulphuric treatment; and as a matter of fact such preacid which is kept in continuous motion by paratory treatment has for instance for copper blowing with steam or air or by other suitable not been found necessary, means. In these acid tanks the starting sheets However, as regards nickel, the practice hithare submerged some time before they are to 15 erto followed entails considerable disadvantages. be used in the deposition tanks, for example Thus it frequently happens that the deposited the ev n e re uc e a d v d as nickel flakes off from the starting sheets already needed during he ex dayin the deposition tanks, which causes short cir- The preparatory treatment is entirely emcuiting and other difficulties, particularly no.- cientand requires little manual labour and inticeable when refining according to the well- D etwnknown Hybinette process with the cathodes The method is of considerable P a al implaced i th Hybinette bag portance in the usual electrolytic refining of In the urs of th subsequent cutting of nickel and is particularly advantageous when the the nickel cathodes into smaller pieces, splitting resulting nickel cathodes are to be used as of the deposited nickel from the starting' sheet anodes in the nickel plating nd y. in wh ch usually takes place. This splitting causes conc it is highly important to avoid splitt n siderable d wb ck of the anodes during preparation or use.

Difiiculties of a similar kind are experiencedv The Practice Of the vent on may be bet- ;0 al in the rt of electrpplating, In th e ter understood by a consideration of the follow..

it is frequently difiicult to make the deposited mg example! metal adhere firmly to the metal to be covered, Nickel is deposited electrolytica y 0n alumi- In order to overcome these diiiiculties, various 1111111 mether Plates d t pped W en of dewith alkaline liquors, comparatively strong acids 400 to 500 such starting sheets are used at the satisfactory results. These known means have h methhd was Worked The Starting S s been considered of little use or too expensive are plmfed in the Pickling bath With about in connection with. the refining of nickel, Sulphuri acid nd generally kept for several whereby it is made possible to avoid the flaking theatment the bath is kept in circulation by and splitting above referred to. This result is blowing in air in Order to r w the acid at the 5 subjecting the starting sheets prior to their keep a uniform temperature of the electrolyte.

, Thus by the use of sulphuric acid, satisfactory I a results have been obtained by treating the sheets 1. In the electrolytic refining of nickel when for a few hours with an acid containing not more using d p s of nickel 0n nickel Starting than 1% concentration, 10 g. H2SO4 in the liter. sheets, t m t d which s s s n bjectin In practice it has been found unnecessary the starting sheets prior to being introduced into to wash the prepared starting sheets before use; the eleotrodeposition cell to the action of dilute I 5 left in contact with the metal for several hours.

2. Process according to claim 1, in which nickel starting sheets after having been subjected to the preparatory treatment in dilute acid are introduced into electrodeposition cells while still moist with the adhering acid.

3. Process according to claim 1, in which the preparatory treatment of the starting sheets takes place in warm sulphuric acid of no more than about 1% concentration.

ANTON MARTIN GRNNINGSZETER. 

